CIA Director John Brennan Urges Caution In U.S. Response To Russia Hacking : The Two-WayJohn Brennan told NPR some retaliation techniques are "beneath this country's greatness." On the war in Syria, Brennan said he does not believe the violence will end, despite the fall of Aleppo.

"I don't think we should resort to some of the tactics and techniques that our adversaries employ against us. I think we need to remember what we're fighting for. We're fighting for our country, our democracy, our way of life, and to engage. And the skulduggery that some of our opponents and adversaries engage in, I think is beneath this country's greatness."

Brennan also discussed the war in Syria and the weeks of horrific violence in the city of Aleppo, where an evacuation appeared to be ending amid freezing weather.

The International Committee of the Red Cross said some 34,000 people have escaped in the week since evacuations began, as we have reported.

Brennan said that, despite the fact that forces loyal to Syrian President Bashar Assad had taken the city, which was controlled by rebels for much of the five-year conflict, he did not believe the violence would end.

"Aleppo's fall, to me, is not a sign that there is going to be an end to this conflict, because I am convinced that many, many of those oppositionists, the ones who are trying to reclaim their country for their families, for their neighbors, for their children, will continue to fight," he said.

"This insurgency is not going to go away until there is some type of viable and genuine political process that will bring to power in Damascus a government that is representative of the Syrian people and really will try to repair and recover from this awful war."

Assad himself appeared to confirm Brennan's assessment earlier this month in an interview with Russian television, in which he said, "Liberating Aleppo doesn't end with liberating the city itself, for it needs to be secured on the outside. Afterwards, identifying which city comes next depends on which city contains the largest number of terrorists."

Brennan also said he felt some responsibility for the horrific bloodshed of the Syrian war. "I think we always like to say that we wish that we would have been able to make a difference, in a way that would have prevented the slide and the situation there," he said.

"There's no way you can divorce yourself, emotionally or mentally, from these situations that you play a role in."

But, he said, he thinks there are limits to American power, saying, "as great a country — as powerful a country — as the United States is, we have, in many areas, limited ability to influence the course of events."